Suspension device for equalizing the strain on hoisting cables



April 5, 1932. J. E. EVANS SUSPENSION DEVICE FOR EQUALIZING THE STRAIN0N HOISTING CABLES Filed June 6, 1950 2 Sheets-Sheet 1 April 5, 1932. J.E. EVANS 1,852,155

SUSPENSIQN DEVICE FOR EQUALIZING THE STRAIN 0N ,HOISTING CABLES FiledJune 6. 1930 2 Sheets-Sheet 2 Patented Apr. 5, 1932 UNITED STATES PAT NTOFFICE JOSEPH E. EVANS, F nnnronn NnIANA, ASSIGNOR TO EvANs ELEVATOREQUAL- IZER COMP NY, or BEDFORI), INDIANA, A oonronATIoN OF INDIANASUSPENSION DEVICE FOR EQUALIZENG- THE STRAIN ON HOISTING CABLESApplication filed June 6,

My invention relates to a hydraulic device devised specifically for theequalization of the load of an elevator car, orcounterweight, upon thegroup of cables by which it is suspended, due to variation in the depthof the grooves in the suspension pulley, variation in the size of thecables, diflerence in stretch of the cables arising from the use of oldand new cables together, and other causes; and is go of the same generaltype as the suspension devices described in my Patents Nos. 1,323,357dated December 2, 1919 and 1,429,070, dated September 12, 1922, and mypending application forpatent Serial No. 393,098, filed September 16,1929. My present invention may be regarded as a modification orimprovement of the construction shown in my said pending application, inwhich improvement I employ a plurality of piston frames sliclingly 29connectedto two suspension cables, and em ploy a novel spring-stressedconnection between the cables and piston frames for the purpose ofyieldingly stressing the cables to a normal intermediate position incase they should shift, or tend to shift,-relatively to each other. Theobject of my invention is the attainment of such desirable modificationsand variations of construction together with incidental improvements andadvantages, as will be apparent from the detailed description of myimproved equalizing device hereinafter given. In the appended claims Ihave set forth the essential elements of my in- P vention, it beingunderstood, however, that my claims are intended to be construedtoinclude all equivalent mechanical parts and modifications of structurewhich'fall within the true spirit of my invention when considered inconnection with the prior art.

In the drawings,

Figure 1 is what will be termed a side view of my novel equalizingdevice, and fragmentary portions of the frame of an elevator car towhich it is shown secured, a portion of the forward frame member ofthecar being broken away to show the portion of the equalizing devicebeyond it;

Fig. 2 is a view as seen at right angles with mounted in the frame ofthe device and each 1930. Serial No. 459,474.

reference to the position of the parts shown in Fig. 1; I Y

' Fig. 3 is a horizontal section in a plane indicated bythe dotted line3 -3 of Fig. 1;

4 Fig. 4 is a horizontal; section on theline 4 1 of Fig. 1; and

Fig. 5 is a view corresponding in part to Fig. 2, but illustrating amodified construction of certain parts. i l i Like reference charactersindicate like parts in all the figures of the drawings.

It will be understood that thegroup of hoisting cables by means of whichthe elevator car (or counterweight, as the case may be) is hoistedthrough the interposed equalizing device to which my invention relates,are arranged to track in the usual manner in parallel grooves formed ina hoisting pulley or drum (not illustrated) at the top of the elevatorshaft, and that the top of the car, or counterweight,-which is arrangedto travel vertically in the elevator chute, is pro,- vided with suitableframe members for the attachment of my novel equalizing device thereto.

Describing now the construction of the equalizing device, thisdevice'includes what I will term a cylinder frame A, clamped to theupper frame member C of the car, and a plurality ofpistons in thecylinders of the cylinder frame severally carried by piston frames Bwhich are slidingly mounted in the cylinder frame and are each connectedto a air of suspension cables. i 1 The cylinder frame A includes a topplate 1 and a bottom plate 2, both formed with cylindrical seats toreceive interposed cylinders 3, and clamping bolts 4 bymeans of whichtheplates andcylinders are firmly secured together., The top plate 1 isformed with channels 5 through which all the cylinders are placed incommunication with each other, and is also formed with one or morefilling and vent passages 65, preferably closed by suitable check valves7 as shown. The bottom plate 2 is orificed :at the bottom of the annularshoulder which forms a cylinder seat,'in alignment with the inner faceof the cylinder thereabove, to form a continuation of the pistonchamber.

The number of cylinders may vary in accordance with the number ofhoisting cables employed, three being illustrated in the presentinstance to provide for six cables, which is the number most frequentlyused.

The cylinder frame above described may be conveniently secured to theelevator car by means of a pair of orificed clamping bars 8-,8, andclamping bolts 9, arranged to en gage such bars and the top plate of theclamping plate, which latter is orificed'to receive them, and to clampthe parts together against the pair of interposed top members C of thecar frame. As shown inFigs. 1 and2 the top plate and clamping bars areprovided with retaining lugs 10 to position the parts and preventdisplacement.

The pistons 11 working in the'piston chambers formed by the cylinders 3(which latter, it will be understood are filled-with a suitable liquidsuch asoil) severally rest loosely upon" the crossbar 12 and nuts 14 bymeans of which the parts are secured together, and are also formed withreduced threaded upper.

ends arranged to engage sockets formed in the horizontal lower portionof a frame bar 15 which has a central vertical portion orificed toreceive a pivot pin 16. This pin provides a bearing for a pair of twinequalizer bars 1717 between which, at their opposite ends, are pivoted apair of blocks 18-18 one at each end, each block being formed withtrunnions 19 engaging bearing orifices in the ad jacent ends of thebars. These blocks are formed with threaded vertical orifices to receivebolts 20 which are secured in any suitable manner, as by the turnbuckles 21 to a pair of adjacent cables of the group of hoisting cables.The piston frames, it will be noted, are disposed transversely of aline'running centrally through the cylinders, but stand in an inclinedposition withreference to a true right angle to such line, so thatthreealternate cables of the group of six may be connected to the endsof the equalizer bars at one side of the equalizer and the three othercables to the other ends of such bars, and all cables will track withapproximate uniformity into the grooves of the hoisting Pu l yl e a Thelower ends of the bolts 20 are arranged 'toftelescopically engage coiledsprings 22,

which are interposed between the upper faces of the horizontal portionsof the frame bars 15 and the nuts 23 which engage such bolts underneaththe equalizer bars. As illus trated, the springs 22 are provided withupper end cups 24 and lower end-cups 25 which it will be understood arewelded to the springs, the lower cups being equipped with anti-frictionrollers 26 engaging'the member 15.

It is obvious that in case of a variation in the travel of the twocables connected to the opposite ends of a given equalizer bar(regarding the twin members 17 as a single bar) the bar will assume aninclined position, while the change in stress of the springs 22associatedwith such bar and pistonframe will yieldingly tend to restorethe bar to its original, and normal, horizontal posithe stress underwhich any, spring -50 is placed by the piston frame with which it'isassociated rising to ahigher position will tend to restore it to itsnormal position, The combined effect of the springs 22 and .55 thereforeis to yieldingly permit different rates of travel of the hoisting cablesinJthe grooves of the hoisting pulley, opposed by a spring tensiontending'to restore them to their original normal position.

In Fig. 5 I have illustrated a modified form of construction of thepiston frames of the equalizer in which the shackle rods 13 P13 of eachframe (corres onding except as otherwise illustrated and escribed to-theshackle rods 13 of the piston frames above described) extend upwardlyfrom their bearing in the top plate 1 cf the cylinder frame to a block30 with which they make screw-threaded engagement. This block isorificed to receive the pivot pin upon which the equalizer bars ofparticular frame are pivoted." ,In this form of piston frame theroller-equipped lower caps secured to the springs which, engage thelower ends of the bolts 20 ride directly upon the upper face of the topplatefll of'the cylinder frame, instead I of upon a portion of thepiston frame. 1"

'I claim: Y l

1. A suspension device for connecting an elevator carto a group ofhoisting cables comprising a cylinder frame secured to said car and aplurality of inter-communicating oilfilled cylinders in said frame,'acorresponding plurality of pistons in said cylinders, acorrespondingplurality of piston frames slidingly mounted in said cylinder frameand'havin g lower crossbars arranged to support'said pistons andequalizing bars centrally pivoted to said piston frames severally nearthe top ends thereof, each bar being connected at its opposite ends to aspread pair of adjacent hoisting cables.

2. A suspension device for connecting an elevator car to a group ofhoisting cables comprising a cylinder frame secured to said car and aplurality of inter-communicating oil-filled cylinders in said frame, acorresponding plurality of pistons in said cylinders, a correspondingplurality of piston frames each including shackle rods slidingly mountedin said cylinder frame and a lower cross-bar arranged to support itsassociated piston and an upper member having a horizontal cross portionsecured to said shackle rods and a vertical central portion; andequalizing bars severally centrally pivoted to said vertical centralportions of the upper piston frame member near the tops thereof, eachbar being connected at its opposite ends to a spread pair of adjacenthoisting cables.

3. A suspension device for connecting an elevator car to a group ofhoisting cables comprising 'a cylinder frame secured to said car and aplurality of inter-communicating oilfilled cylinders in said frame, acorresponding plurality of pistons in said cylinders, a correspondingplurality of piston frames slidingly mounted in said cylinder frame andhaving lower crossbars arranged to support said pistons, equalizing barscentrally pivoted to said piston frames severally near the top endsthereof, each bar being connected at its opposite ends to a spread pairof adjacent hoisting cables, and spring means connected to saidequalizer bars severally and arranged to yieldingly oppose change ofangular position of said bars.

A. A suspension device for connecting an elevator car to a group ofhoisting cables comprising a cylinder frame secured to said car and aplurality of inter-communicating oilfilled cylinders in said frame, acorresponding plurality of pistons in said cylinders, a correspondingplurality of piston frames slidingly mounted in said cylinder frame andhaving lower crossbars arranged to support said pistons, equalizing barscentrally pivoted to said piston frames severally near the top endsthereof, each bar being connected at its opposite ends to a spread pairof adjacent hoisting cables, and spring means interposed between each ofsaid piston frames and its associated equalizer bar arranged toyieldingly oppose change of angular position of said bar.

5. A suspension device for connecting an elevator car to a, group ofhoisting cables comprising a cylinder frame secured to said car and aplurality of inter-communicating oilfilled cylinders in said frame, acorresponding plurality of pistons in said cylinders, a correspondinglurality of piston frames each including shac 1e rods slidingly mountedin said cylinder frame and a lower crossbar ar-V ranged to support itsassociated piston and an upper member having a horizontal cross portionsecured to said shackle rods and a vertical central portion equalizingbars sev- Y tion of said bars.

6. An equalizing device according to claim 3 in which said spring meansconsists of a pair of coiled compression springs interposed betweenopposite ends of the particular equaltherebelow.

7 An equalizmg device according to claim 3 in which said spring meansconsists of a pair of coiled compression springs which are connected attheir upper ends to opposite ends of the equalizer bar and are providedat their lower ends with cap members equipped with rollers bearing uponfaces on portions of the device below said springs.

8. An equalizing device according to claim 3 in which-the pairs ofhoisting cables are connected to, bolts which are pivotally connected toand extend below the ends of the particular equalizer bar, and in whichsaid spring means consists of a pair of coiled compression springstelescopically engaging the ends of the bolts.

9. A suspension device for connecting an elevator car to a group ofhoisting cables comprising a cylinder frame secured to said car and aplurality of inter-communicating oilfilled cylinders in said frame, acorresponding plurality of pistons in said cylinders, a correspondingplurality of piston frames slidingly mounted in said cylinder frame andhaving lower crossbars arranged to support said pistons, springsinterposed between said cylinder frame and said crossbars, equalizingbars centrally pivoted to said piston frames severally near the top endsthereof, each bar being connected at its opposite ends to a spread pairof adjacent hoisting cables, and springs interposed between each o-fsaidpiston frames and its associated equalizer bar arranged to yieldinglyoppose change of angular position of said bar.

In testimony whereof, I have subscribed my name.

JOSEPH E. EVANS.

izer bar and facesupon portions of the device

